As a means for the preserving of the individual, the intellect unfolds its principle powers in dissimulation, which is the means by which weaker, less robust individuals preserve themselves-since they have been denied the chance to wage the battle for existence with horns or with the sharp teeth of beasts of prey, This art of dissimulation reaches its peak in man. Deception, flattering, lying, deluding, talking behind the back, putting up a false front, living in borrowed splendor, wearing a mask, hiding behind convention, playing a role for others and for oneself-in short, a continuous fluttering around the solitary flame of vanity-is so much the rule and the law among men that there is almost nothing which is less comprehensible than how an honest and pure drive for truth could have arisen among them. They are deeply immersed in illusions and in dream images; their eyes merely glide over the surface of things and see "forms."

http://www.publicappeal.org/library/nietzsche/Nietzsche_various/on_truth_and_lies.htm

[ Two realities exist: the real world, and the fantasy world created by consensual agreement as to value and place of objects and people in civilizations. Only the first really has any permanence, since the latter is dependent upon our dying civilizations being healthy. Truth is a descriptive term, not something that exists. ]